A preferred package for milk and juice is the gable-top package. The gable-top package is typically composed of a paperboard material coated on its interior and exterior surfaces with a thermoplastic material such as polyethylene. A further barrier, such as foil, can be provided on the interior of the package intermediate the paperboard and the layers, for packaging citrus juices and the like.
The package is formed from a blank in a paper converting process. The blank has a plurality of crease lines formed therein for properly folding the blank into the desired package shape. The unconstructed form or blank has a plurality of side panels (typically four) and corresponding top and bottom panels. The side panels define the front, rear and side walls of the package, the top panels form the well-known gable-top and the bottom panels fold and are sealed to one another to form a liquid and gas impervious bottom package seal.
In the converting process, the carton blanks are cut from sheet stock previously coated with the polymer layers. As such, while the face areas of the paperboard are coated, the raw paper edges are uncoated and thus are more susceptible to absorption of moisture. Moisture absorbed into the paperboard material may comprise the integrity of the carton and may result in a reduced shelf life for the packaged product.
The carton bottom is particularly susceptible to moisture absorption. Moisture can be absorbed into raw edges from both the interior and the exterior of the package. To this end, various configurations and devices have been developed in an effort to reduce the opportunity for raw edge absorption at the carton bottom. Configurations are disclosed in Christensen, U.S. Pat. No. 6,027,015 and U.S. Pat. No. 5,988,490 and Johansson et al., U.S. Pat. No. 5,845,840 which patents are commonly assigned herewith and are incorporated herein by reference. The aforementioned patents work well in preventing raw edge liquid absorption from an exterior source, however, they do not address the absorption of liquid from an carton interior source.
Accordingly, there exists a need for a carton and a carton blank configuration that eliminates the exposure of the raw edges to moisture from both interior as well exterior conditions. Desirably, such a configuration can be accommodated on known form, fill and seal packaging machines with little to no modification to existing components.